Field of the Invention
The present invention relates to a ball rotational direction detecting system that detects the orientation of the rotation axis and the rotational direction of a ball moving in midair with respect to the traveling direction and the gravity direction of the ball.
Description of the Related Art
For example, JP-A-2014-160025 discloses a rotational speed detecting device that detects the rotational speed of a ball moving in midair such as a ball thrown by a baseball pitcher. This rotational speed detecting device is configured so as to be able to calculate the rotational speed of the ball moving in midair based on time variations in the output of a magnetic sensor provided in the ball. With this rotational speed detecting device, it is possible to detect the rotational speed of a ball without using a large-scale apparatus.